Action, Martial Arts, Fantasy, Shounen, Drama, Historical

In a world that resembles samurai period Japan with a light supernatural twist, Renka is a manslayer with an unknown past and mysterious intentions. As he goes on to work eliminating targets and more, his past starts to unveil and together with the power in his right hand, which he calls merciful, a series of events might lead him and those around him to frontiers they never thought possible.